1. Field of the Invention
This invention relates to a disc loading mechanism for loading a disc, such as an optical disc, on a disc driving apparatus adapted for recording desired information signals on and reproducing the recorded information signals from the disc.
2. Description of the Related Art
There has hitherto been known a disc driving apparatus in which a disc, such as an optical disc, is used as a recording medium of an external storage device for an electronic computer and in which information signals from the computer are recorded on or reproduced from the disc.
The disc driving apparatus is provided with a disc transport member supported for horizontal movement through the inside and the outside of the main body of the apparatus for transporting the disc set thereon through the inside and the outside of the main body of the apparatus, a disc table supporting base plate setting thereon a disc table for rotating the disc transported by the disc transport member, and a chucking member arranged facing the disc table with the disc transport member inbetween for chucking the disc in cooperation with the disc table. The disc table supporting base plate is supported for rotation in a direction towards and away from the disc transport member.
The disc loading mechanism transports the disc set on the disc transport member through the inside and the outside of the main body of the apparatus by the disc transport member being moved by a driving motor through the inside and the outside of the main body of the apparatus. When the disc transport member setting the disc thereon is moved by the driving motor through the inside and the outside of the apparatus, the disc table supporting base plate is rotated by the driving motor in a direction approaching the disc transport member for projecting the disc table into the inside of the disc transport member. With the disc table thus projected into the inside of the disc transport member, the disc set on the disc transport member is set on the disc table while being pressed against the chucking member. The disc set on the disc table and pressed against the chucking member is mounted on the disc table and loaded in position so as to be rotated in unison with the disc table.
That is, the disc loading mechanism is so designed that the disc transport member for transporting the disc through the inside and the outside of the main body of the apparatus is moved horizontally by the driving motor and, after the disc within the main body of the apparatus has been moved by the disc transport member to a position of chucking the disc on the disc table, the disc table supporting base plate is rotated by the driving motor in the direction of approaching the disc transport member for mounting the disc on the disc table by cooperation of the disc table with the chucking member.
Meanwhile, there are provided on the disc table supporting base plate, besides the abovementioned disc table, a spindle motor for rotationally driving the disc table, an optical pickup device for recording or reproducing information signals on or from the disc and a feed device for feeding the optical pickup device. For this reason, the disc table supporting base plate is increased in weight. An extremely large force is required for supporting the heavy base plate by means of a rotating supporting shaft and rotating the base plate about the rotating supporting shaft as a center of rotation. Hence, a large size driving motor is required as a driving source, as a result of which the disc driving apparatus becomes bulky in size.